Simplify the following expression: $x = \dfrac{1}{4t} + \dfrac{7}{2t}$
Solution: In order to add expressions, they must have a common denominator. The smallest common denominator is the least common multiple of $4t$ and $2t$ $\lcm(4t, 2t) = 4t$ $ x = \dfrac{1}{1} \cdot \dfrac{1}{4t} + \dfrac{2}{2} \cdot \dfrac{7}{2t} $ $x = \dfrac{1}{4t} + \dfrac{14}{4t}$ $x = \dfrac{1 +14}{4t}$ $x = \dfrac{15}{4t}$